Niosomes: a potential tool for novel drug delivery

Abstract

Vesicular drug delivery system are novel means to improve the bioavailability of the encapsulated drug along with numerous advantages over conventional drug delivery systems. Liposomes were first in such type of delivery systems but it was not so successful due to their numerous drawbacks. Niosomes or non ionic surfactant vesicles are formed from self assembly of hydrated surfactant monomers. They are formulated by non ionic surfactants but various ionic amphiphiles like di cetyl phosphate, sodium deoxycholate and stearylamine etc. are also incorporated inorder to achieve a stable vesicular suspension by inducing negative or positive charge. The most striking feature of such delivery system is that it can be used to encapsulate both hydrophobic as well as hydrophilic drug. The emphasis of this type of vesicular drug delivery system is placed over the slow release of drug in a controlled manner, resulting into sustained activity, reduced toxicity, protection of active moiety, targeting, modification in distribution profile of drugs and enhancing the bioavailability of encapsulated drug. This article summarizes the merits of niosomal drug delivery system over conventional drug therapy, its structural components, factors affecting its formation, method of preparation, evaluation techniques, therapeutic applications and patents.